Skorzeny,
Have to wade in a confirm Tecolote's statement about current 10 rnd. Glock mags. The 10 rounders that came with my new 19 a couple months back fed any ball ammo and narrow-mouthed HP with ease. Hydro-Shocks, however(which aren't even that wide), gave a consistent failure to go up the ramp. Same with Starfire El Dorados, Cor Bons, etc. Asked around and got a lot of shrugs.
Went over to Glockmeister.com and asked about my problem (follow the 'Ask the Smith' link). Got an almost immediate reply from them telling me it was the followers. Advised me to switch them out for some #3 followers and the problem would go away. I happened to have some older 10 rounders for my 17. Pulled the followers and inserted them in the 19 mags - guess what? The problem went away.
If you look at the follower from your new 10 rnd mag next to the one in your older 15 rnd one, you will notice that the new follower is markedly flat. Glockmeister has pictures of the various generations of Glock mags on their site for you to familiarize yourself with. Hope this helps. It was sure a load of frustration off my mind when I finally got this worked out.
Best,
- Drew